The ISS is the most sophisticated human-made structure ever built. Weighing more than 400 tonnes and covering an area as big as a football pitch, the ISS orbits Earth approximately 400 km above the surface, travelling at a speed of 27,600 km/h. This means it circumnavigates the earth every 90 minutes.

The space station is basically made up of a number of pressurized modules that serve as scientific laboratories, docking ports, airlocks, storage and habitation areas. Then there is a 'truss' that forms the spine of the space station. The truss consists of 12 metal lattice structures that span the 109 meter width of the space station, containing many of the components that keep the ISS alive, such as power, cooling, communications, altitude and control systems. The truss also houses a number of logistics platforms where many spare components have been pre-stored. Attached to the left side of the truss are radiators (waffle-shaped panels with ammonia flowing through them, to avoid excess heat that builds up in the station).

At each end of the truss are giant solar arrays, which turn sunlight into electricity. The truss has a joint that enables these solar panels to rotate 360 degrees to track the Sun. These wide, flat solar panels cover a total area of approximately 2,500 square meters  and produce up to 120 kilowatts of electricity, sufficient power for 40 average homes. During darkness, batteries stored in the truss, which are charged during daylight, provide power to the ISS.